fcfa4c9589
Use return(0) for main() instead of exit(0). Makes it a wee bit smaller.
130 lines
3.5 KiB
C
130 lines
3.5 KiB
C
/*
|
|
* Copyright (c) 1988, 1993, 1994
|
|
* The Regents of the University of California. All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
* 3. All advertising materials mentioning features or use of this software
|
|
* must display the following acknowledgement:
|
|
* This product includes software developed by the University of
|
|
* California, Berkeley and its contributors.
|
|
* 4. Neither the name of the University nor the names of its contributors
|
|
* may be used to endorse or promote products derived from this software
|
|
* without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
* SUCH DAMAGE.
|
|
*/
|
|
|
|
#if 0
|
|
#ifndef lint
|
|
static char const copyright[] =
|
|
"@(#) Copyright (c) 1988, 1993, 1994\n\
|
|
The Regents of the University of California. All rights reserved.\n";
|
|
#endif /* not lint */
|
|
|
|
#ifndef lint
|
|
static char sccsid[] = "@(#)sleep.c 8.3 (Berkeley) 4/2/94";
|
|
#endif /* not lint */
|
|
#endif
|
|
#include <sys/cdefs.h>
|
|
__FBSDID("$FreeBSD$");
|
|
|
|
#include <ctype.h>
|
|
#include <limits.h>
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <time.h>
|
|
#include <unistd.h>
|
|
|
|
void usage(void);
|
|
|
|
int
|
|
main(int argc, char *argv[])
|
|
{
|
|
struct timespec time_to_sleep;
|
|
long l;
|
|
int neg;
|
|
char *p;
|
|
|
|
if (argc != 2) {
|
|
usage();
|
|
return(1);
|
|
}
|
|
|
|
p = argv[1];
|
|
|
|
/* Skip over leading whitespaces. */
|
|
while (isspace((unsigned char)*p))
|
|
++p;
|
|
|
|
/* Check for optional `+' or `-' sign. */
|
|
neg = 0;
|
|
if (*p == '-') {
|
|
neg = 1;
|
|
++p;
|
|
if (!isdigit((unsigned char)*p) && *p != '.') {
|
|
usage();
|
|
return(1);
|
|
}
|
|
}
|
|
else if (*p == '+')
|
|
++p;
|
|
|
|
/* Calculate seconds. */
|
|
if (isdigit((unsigned char)*p)) {
|
|
l = strtol(p, &p, 10);
|
|
if (l > INT_MAX) {
|
|
/*
|
|
* Avoid overflow when `seconds' is huge. This assumes
|
|
* that the maximum value for a time_t is >= INT_MAX.
|
|
*/
|
|
l = INT_MAX;
|
|
}
|
|
} else
|
|
l = 0;
|
|
time_to_sleep.tv_sec = (time_t)l;
|
|
|
|
/* Calculate nanoseconds. */
|
|
time_to_sleep.tv_nsec = 0;
|
|
|
|
if (*p == '.') { /* Decimal point. */
|
|
l = 100000000L;
|
|
do {
|
|
if (isdigit((unsigned char)*++p))
|
|
time_to_sleep.tv_nsec += (*p - '0') * l;
|
|
else
|
|
break;
|
|
l /= 10;
|
|
} while (l);
|
|
}
|
|
|
|
if (!neg && (time_to_sleep.tv_sec > 0 || time_to_sleep.tv_nsec > 0))
|
|
(void)nanosleep(&time_to_sleep, (struct timespec *)NULL);
|
|
|
|
return(0);
|
|
}
|
|
|
|
void
|
|
usage(void)
|
|
{
|
|
const char msg[] = "usage: sleep seconds\n";
|
|
|
|
write(STDERR_FILENO, msg, sizeof(msg) - 1);
|
|
}
|